1. Technical Field
Example embodiments of the present invention relate in general to provision of multimedia services and more specifically to a transmitter and a receiver for providing multi-layered multimedia services and a method thereof.
2. Related Art
Along with the speedup of wireless networks and the Internet, multimedia content services focusing on video are becoming more common in a broadcasting and communication convergence environment such as video streaming, mobile broadcast, or IPTV. In particular, with the advent of mobile terminals such as smart phones, demands for mobile multimedia services have been rapidly increased.
The multimedia services require provision of various types of multimedia information having different information characteristics. In addition, there are various types of terminals capable of utilizing multimedia services, and various types of service qualities capable of being implemented for each terminal.
In order to effectively cope with this diversity, service scalability is required. In addition, since a channel state continuously changes in a mobile broadcast, it is necessary to ensure graceful performance degradation in order to prevent sudden degradation of service quality.
Since a transmitter does not have information (terminal type, required service quality, channel state, or the like) about a terminal in a broadcast system, it is difficult to effectively provide multimedia services to meet the needs of users.
That is, most of the existing broadcasting systems are designed in consideration of the worst terminal. For example, in an enhanced Multimedia Multicast Broadcast Services (e-MBMS) of 3GPP, considering a case in which a reception antenna of a terminal is one, and a channel status is very bad, a QPSK modulation having the lowest transmission efficiency and a Single Input Single Output (SISO) transmission method are adopted.
However, such an approach has a problem that, although a terminal having multiple reception antennas may receive information with high transmission efficiency in a superior channel environment, high-quality multimedia services may not be achieved due to a limitation in the quantity of information to be transmitted. Therefore, for the efficient multimedia services, a transmitter should provide high-quality multimedia services and a terminal should determine service quality depending on terminal performance and channel status.
Scalable video coding (SVC) ensures scalability as leading technology, and many standard organizations have adopted SVC as a standard. SVC represents input signals as information of several layers having different information priorities.
In order to efficiently transmit such layer information having different information priorities, unequal error protection (UEP) transmission in which a degree of error protection differs depending on information priorities should be performed. Since UEP transmission should be configured by comprehensively and mutually considering a description part and a transmission part of information, the design becomes complex, and the structure and operation become complex.
A transmitter for providing high-quality multimedia services is required to transmit information at a high speed, and for this, Multiple Input Multiple Output (MIMO) technology may be suitably utilized. In order to perform transmission of information by the MIMO technology, the number of reception antennas is required to be the same as or larger than the number of transmission antennas. However, in an existing mobile broadcast, since there are many cases in which the number of reception antennas of a terminal is smaller than the number of transmission antennas of a base station, it is difficult to utilize the MIMO technology.